1. Field of the Invention
The present invention relates to a production process for a structure and a production process for a liquid discharge head.
2. Description of the Related Art
Technique to form a fine structure on a substrate is applied to the field of MEMS. The application thereof includes a liquid discharge head used for an ink jet head.
Technology development has been continued for improving performance such as smaller droplets, higher driving frequency and more discharge ports in order to enhance recording properties of ink jet heads. Above all, a demand for smaller droplets for improving picture quality is strong, and a technology for manufacturing a fine structure with high precision which functions as an ink flow channel and a nozzle has been demanded. As such a technology, photolithography is excellent in both precision and simplicity of the process, and a process for producing an ink jet head by photolithography is disclosed in U.S. Pat. No. 5,478,606.
In recent years, however, further finer nozzle structures are becoming demanded to realize higher nozzle density for achieving finer droplets, which is for improving picture quality, as well as speed-up of operation and it has been recognized that the above-mentioned production process involves various problems. For example, when the finely designed structure results in decrease in the intervals of the flow channels, adhesion between the flow channel forming layer and the substrate may deteriorate. In the meantime, it becomes important to secure the liquid flow channel cross-sectional area so as to maintain ink discharging performance.
A method of processing the substrate by etching to secure this ink flow channel cross-sectional area of the ink jet head is disclosed in U.S. Pat. No. 7,575,303.
This production process requires, however, complicated process and an expensive apparatus, and thus simpler and less costly production processes have been demanded.